Coherent Imaging Laser Source

ABSTRACT: Arete proposes a seeded Er:YAG MOPA system with narrow linewidth at 1617 nm and energy scalability surpassing program requirements. A novel seed system provides instantaneous multiple octave wavelength difference spanning for phase resolution control while eliminating strict tuning requirements. Commercially available spectrum stabilized diode lasers provide<100 kHz linewidth for injection locking a Pound-Drever-Hall servo controlled laser cavity. A 1532 nm fiber coupled pump powers the EO Q-switched ring cavity laser providing excellent beam quality and efficient thermal management. A solid state amplifier delivers pulse energies in the 10 mJ range. Identical, synchronized laser transmitters provide dual-color pulse doublets for coherent imaging of long range targets with arbitrary temporal pulse spacing. Scaling to multi-color imaging is straightforward and linear in cost and complexity. This Phase I effort is a high confidence, hardware-based demonstration of system performance with commercially available components. Arete"s approach provides a low SWaP, field worthy alternative to other architectures. BENEFIT: The concepts and hardware developed in this program have a wide range of relatively near-term military (tactical, theater and strategic) and other (surveillance/homeland security) applications. Tactical and surveillance adaptations would be the largest potential near-term markets. Our approach could be readily and cost effectively adapted to fielding of compact eyesafe laser radars and serve as high-accuracy optical trackers and target identifiers. Our approach can be used to generate high resolution 3-dimensional images of targets or fields at long stand-off distances.